Stack of interfolded absorbent sheet products

ABSTRACT

A stack of interfolded absorbent sheet products comprises a plurality of absorbent sheets each of which is itself folded at least twice about axes that are perpendicular to one another. The absorbent sheets have an embossed surface relief of a predetermined pattern or design. Each of the absorbent sheets within the stack comprises at least one pair of panels sandwiched between a pair of adjacent panels of another of the absorbent sheets in the stack.

The present application is a continuation of U.S. application Ser. No.10/660,694 filed on Sep. 12, 2003 and now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a stack of interfolded absorbent sheetproducts, and preferably, but not necessarily, to a stack of interfoldedpaper napkins bearing a predetermined pattern imparted by embossing orby formation by the Through-Air Drying (“TAD” ) technique.

2. Description of Related Art

In commercial food service establishments and public restrooms, foldedpaper products such as paper napkins are typically provided indispensers from which the products may be withdrawn by the patrons ofthose establishments. Whereas the highest quality paper napkins areinvariably “server-controlled,” i.e., delivered individually by a waiteror waitress, it is nevertheless desired to provide paper products in theuser-dispensed application that are perceived as being of relativelyhigher quality.

Interfolded paper products, and especially interfolded paper napkins,have the advantage that they can be loaded into a dispenser whosefaceplate cooperates with the stack of napkins to encourage users toremove napkins one at a time. This results in users taking fewer napkinsthan if it were possible or encouraged to remove a group of napkinssimultaneously, although the paper product stack according to theinvention may be used in dispensers that promote either one at a time orgroup dispensing.

Interfolded paper napkins applied to a user-dispensed environment areprincipally single folded only, in the marketplace at present. Patentliterature describes a variety of arrangements of interfolded papernapkins having plural parallel folds, for example, in U.S. Pat. Nos.5,118,554, 6,090,467 and 6,213,346.

Paper napkins that are single folded only (sometimes also called“half-folded” when the fold bisects the napkin, or “off-folded” when itdoes not) have the disadvantage that, in order to achieve a given totalabsorbency, the basis weight of the unfolded napkin sheet must berelatively high. This in turn causes the napkin to have relatively lowsoftness and drape properties, both of which properties are important tothe user's perception of the total quality of the napkin. The provisionof plural parallel folds in a napkin has the obvious limitation that thenapkin will have a relatively elongated shape in the direction parallelto the folds, unless the starting blank is cut to a relatively moreelongated shape in the direction perpendicular to the folds.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to address and alleviate, atleast in part, the disadvantages described above in connection with theprior art, by providing a stack of interfolded absorbent sheet products,each of which products is itself folded at least twice about axes thatare perpendicular to one another, the products moreover comprising asurface relief of a predetermined pattern or design imparted byembossing or by TAD formation.

The folded absorbent sheet products according to the invention arepreferably single ply paper napkins having a basis weight of from about10 to 20 lb per unfolded sheet. More preferably, the basis weight of thenapkins according to the invention is from about 11 to about 17 lb,still more preferably from about 12 to about 15 lb, and most preferablyabout 13 lb. The expression of basis weight in pounds as used herein iswith reference to a stack of 500 unfolded single ply sheets eachmeasuring 24 by 36 inches.

The term “absorbent sheet products” as used herein embraces not onlypaper products such as paper napkins, but also absorbent nonwovenmaterials not normally classed as papers or tissues. Such nonwovenmaterials include pure nonwovens and hybrid nonwoven/pulp webs whoseproperties are similar to those of tissue paper, but which are based forexample on nonwoven or airlaid materials containing low amounts ofsynthetic fibers, binders, wet strength agents and the like. An exampleof such a material would be a wetlaid or foam-formed hydraulicallyentangled nonwoven material comprising at least 30% by weight pulpfibers and at least 20% by weight manmade fibers or filaments.

In one embodiment, the folded absorbent sheet products are paper napkinseach having two folds, the two folds each bisecting the napkin and beingperpendicular to one another. Such a napkin is referred to herein as a“quarter folded” napkin, in that the folded napkin is about one quarterthe size of the unfolded sheet. Such a napkin may also be considered asa “four-panel” napkin, in that the perpendicular folds delineate fourregions in the initial napkin sheet.

Other contemplated embodiments of the invention include six panel andeight panel napkins. Four example, in a six panel napkin, the initialsheet comprises one fold in the longitudinal direction of the sheet andtwo folds in the transverse direction, such that the resulting foldedsheet comprises six equally sized panels. The eight panel napkin has asimilar structure, but with three parallel folds in the transversedirection. In the case of eight equally sized panels, the final twofolds may be generated simultaneously, by folding a quarter-foldednapkin once again in half.

The folded absorbent sheet products according to the invention arepreferably discrete, that is, entirely detached from one another.However, it is also within the scope of the invention that the stack ofabsorbent sheet products be interconnected by “tabs”, with the pullingforce at the time of withdrawing a single absorbent sheet productthrough a dispensing opening being greater than or equal to the forcerequired to tear the tabs connecting adjacent absorbent sheet products.

The interfolding arrangement described herein recommends that the stackof absorbent sheet products be formed in a pair of parallel “lanes”,such that, when the products are interconnected by tabs, it is in factalternate absorbent sheet products that are joined together, rather thanconsecutive absorbent sheet products.

The invention also contemplates the use of the novel stack of absorbentsheet products in a variety of dispensers. At present, a dispenserhaving downwardly-directed opening is preferred, in which the stack ofabsorbent sheet products is oriented at one or more angles that areoblique or vertical. However, the stack of interfolded absorbent sheetproducts may also be used in conjunction with a dispenser having anupwardly directed opening, or a lateral opening.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention will become moreapparent after reading the following detailed description of preferredembodiments of the invention, given with reference to the accompanyingdrawings, in which:

FIG. 1( a) is a schematic representation of the interfold configurationof a stack of folded absorbent sheet products according to a firstembodiment of the invention;

FIG. 1( b) is a schematic cross-sectional view of the napkin stack ofthe FIG. 1( a) embodiment;

FIG. 2( a) is a schematic representation of the interfold configurationof a stack of folded absorbent sheet products according to a secondembodiment of the invention;

FIG. 2( b) is a schematic cross-sectional view of the napkin stack ofthe FIG. 2( a) embodiment;

FIG. 3( a) is a schematic representation of the interfold configurationof a stack of folded absorbent sheet products according to a thirdembodiment of the invention;

FIG. 3( b) is a schematic cross-sectional view of the napkin stack ofthe FIG. 3( a) embodiment;

FIG. 4 is a perspective view showing an embodiment of a dispenser forholding and dispensing one-by-one the stack of absorbent sheet productsaccording to the invention;

FIG. 5 is an exploded perspective view showing the principal componentsof the dispenser according to FIG. 4; and

FIG. 6 is a perspective view of an individual unfolded napkin accordingto the FIGS. 1( a) and 1(b) embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1( a), 1(b) and 6 depict the above-discussed “quarter-folded”embodiment of the invention. As seen in FIGS. 1( a) and 1(b), theinterfolding of adjacent sheets is such that any given napkin within thestack receives, between a pair of adjacent panels of the given napkin, apair of adjacent panels of each of an upper and a lower napkin withinthe stack.

Such an interfolding arrangement is shown in the context of singlefolded paper towels, in U.S. Pat. Nos. 1,427,420 and 1,632,446. Aquarter-fold interfold arrangement has been described before inconnection with pop-up tissue dispensers (see EP 0 286 538 B1 and EP 0302 382 A1). Web interfolding machines are described in U.S. Pat. Nos.3,285,599 and 3,291,479, the entireties of which patents are herebyexpressly incorporated by reference.

Whereas the embossed folded absorbent sheet products according to theinvention are preferably paper napkins, as discussed in U.S. Pat. No.5,300,347, facial tissue is rarely embossed. The embossed facial tissuedescribed in that patent not being disclosed as a folded or interfoldedproduct, whereas in the two European patent documents identified above,the facial tissue described therein is not disclosed to be embossed.

FIG. 6 illustrates that the folded and interfolded absorbent sheetproducts according to the invention are embossed. As used herein, theterm “embossed” connotes a three-dimensional low relief pattern of adistinct pattern or image. Such embossing may be applied by conventionalembossing rollers during the converting phase of the napkinmanufacturing, preferably upstream of the folding and interfolding,and/or may be formed by a selected pattern of the TAD fabric, if thenapkins are made by the TAD technique. The term “embossed” as usedherein does not embrace, however, any incidental surface roughnessimparted to a napkin sheet by the forming fabric used in a traditionalYankee cylinder/dry crepe forming line, which surface roughness does notdisplay any predetermined pattern to the unaided eye.

The specific pattern embossed onto the napkins according to theinvention is not critical, with that illustrated by way of example inFIG. 6 being as shown in commonly-owned U.S. Design Patent No. D462,530.The embossing may be of a continuous pattern over the entire surface ofthe sheet, as is the case for FIG. 6, or the embossing may be applied toselected regions of the sheet, e.g. along a periphery or a borderthereof.

When the absorbent sheet products according to the invention are to beused in a food establishment, particularly a fast food franchise, it iscontemplated that the embossing might take the form of a logo of therestaurant in which the napkins will be used, either alone or incombination with a decorative border.

The basis weight of the absorbent sheet products according to theinvention is preferably within the range of a high quality napkin, andthus less than that of commercially available single folded paperproducts, whose higher basis weight places them closer to the categoryof paper towels. The embodiment of FIGS. 1( a), 1(b) and 6 has a basisweight of about 13 lb, calculated as defined above. However, it will beappreciated by those skilled in the art that the basis weight may varyover a broader range, from about 10 to 20 lb per unfolded sheet, morepreferably from about 11 to about 17 lb, and still more preferably fromabout 12 to about 15 lb.

While this range of basis weights is greater than that commonly used forfacial tissue (wherein a basis weight of 8½ to 9 per ply is typical), itis distinctly less than the basis weights found in commerciallyavailable single-fold napkin/towels, which tend to have basis weights inexcess of 20 lb. Thus, by providing a paper napkin wherein the sheet hasa relatively low basis weight, yet the napkin is folded to have at leastfour panels, the invention provides a napkin that is comparativelysofter and has improved drape properties in relation to single foldproducts.

The paper napkin of FIGS. 1( a), 1(b) and 6 is formed from a single plywhose dimensions are preferably about 8½″×13″, such that the foldednapkin will have dimensions of about 4¼×6½″. Obviously, these dimensionsmay be varied to suit the particular application in question. FIGS. 1(a) and 1(b) are taken in planes parallel to the short sides of thenapkin stack. FIG. 1( b) illustrates the point that each napkin isfolded not only as shown in the figure, but also about a perpendicularline of folding parallel to or coincident with the plane of the drawing.Therefore, the folds visible in FIGS. 1( a) and 1(b) are those extendingacross the long dimension of the napkins, whereas the folds not visibleare those extending across the short dimension of the napkins.

With reference to FIG. 1( b), it will be appreciated that, in thisembodiment, each napkin within the stack receives between its twoinwardly facing adjacent panels a pair of adjacent panels from each oftwo napkins disposed respectively above and below it in the stack.

In the six-panel embodiment of FIGS. 2( a) and 2(b), on the other hand,the uppermost napkin has its four lower panels sandwiched between twoadjacent panels of the next lower napkin in the stack, whose lower fourpanels are in turn sandwiched between the lowermost two panels of thetop napkin, and the uppermost two panels of the third napkin. In FIG. 2(b) (and also in FIG. 3( b)), the cross-sectional lines are added to aidvisual differentiation of adjacent panel pairs, but are not intended toreflect a solid thickness.

In the eight-panel embodiment of FIGS. 3( a) and 3(b), the uppermostnapkin has its four middle panels sandwiched between two of the upperfour panels of the second napkin in the stack, whereas the four middlepanels of the second napkin are sandwiched between two of the fourlowermost panels of the first napkin. The two lowermost panels of thesecond napkin and the two uppermost panels of the fourth napkin aresandwiched between two of the four uppermost panels of the third napkin.

The principal components of a dispenser that is preferred for use indispensing the napkin stacks according to the invention, as shown inFIG. 4, include a main dispenser body portion 1, which terminatesdownwardly in a faceplate 4 having a dispensing opening through whichnapkins are withdrawn one-by-one. The faceplate 4 is preferablyremovable from the body portion 1, for example as shown in FIG. 3.

A cover 2 closes the front of the main body portion 1, and is openableto permit reloading of fresh napkins into the main body portion 1. Thecover 2 is preferably transparent, so that the quantity of napkinsremaining in the dispenser can be observed without the need to open thesame; whereas the main body portion 1 is preferably opaque.

A stand 3 supports the dispenser on an underlying horizontal surface,and also positions the dispenser at the desired angle relative to suchsurface. The stand 3 is preferably also removable from the body portion1, as shown in FIG. 3, which provides advantages discussed herein;however, the stand 3 could also be formed in one piece with, orpermanently secured to, the main body portion 1.

The dispenser body and stand shown in FIGS. 4 and 5 is that presentlypreferred by the inventors; however, the invention is applicable to avariety of other dispenser shapes and types; consequently, theaccompanying claims that are directed to the absorbent sheet productstack do not require the presence of a dispenser, and the accompanyingclaims that recite a dispenser in combination with a absorbent sheetproduct stack are not intended to be limited to any particular dispensershape or type, unless the claim so states.

The exploded view of FIG. 5 shows a number of advantageous structuraldetails of the FIG. 4 dispenser. All of the components are preferablyformed of injection-molded plastic. The various connecting structures ofthe component parts thereby have sufficient inherent resiliency todeform enough to enter the mating parts on the adjacent component, forease of assembly and disassembly.

The transparent cover 2 is connected to the main body portion 1 via theslotted openings 15, which fit over the flanged bosses 14 formed on themain body portion 1. Only one opening/boss pair 14, 15 is visible inFIG. 2; however, the dispenser of this embodiment is symmetrical about alongitudinal bisecting plane parallel to its sides. The cover can beopened by pivoting it about the common axis of the bosses 14 andopenings 15. The range of angular movement of the cover 2 relative tothe main body portion 1 permits fully exposing the interior of the mainbody portion 1, thereby to allow unimpeded access for refilling thedispenser.

Cleats 18 snap fit to the inside edge portions of cover 2 to hold thecover in the closed position. Those cleats can be released by exertinginwardly-directed pressure on the depressions 19 formed on the outsideof the main body portion 1.

The cover 2 of this embodiment also has an inner width slightly greaterthan the outer width of the main body portion 1, so that the twocomponents overlap in the closed position. The main body portion 1therefore includes a laterally-outwardly projecting flange 16 on one orboth sides, which registers with the complementary-shaped edge 17 of thecover 2, and serves as a secure stop in the closed position.

The main body portion 1 is closed at its lower end by the one-by-onefaceplate 4 having a dispensing opening 5. The faceplate 4 cooperateswith the stack of napkins held within the dispenser to permitone-at-a-time dispensing of such napkins, as will be described ingreater detail below. The faceplate 4 is detachably connected to themain body portion 1 by resilient cleats 12 that mate with correspondingslots 13 formed on the main body portion 1.

The main body portion 1 is detachably connected to the stand 3 by acombination of brackets 9 on the stand that engage slots 10 on the mainbody portion 1, resilient cleats 7 on the stand 3 that snap fit intocorresponding openings 8 on the main body portion 1, and roundprojections 21 on the stand 3 that engage openings 22 on the main bodyportion 1 to ensure a correct positional registration.

The main body portion 1 also includes recessed openings 11 that permitthe main body portion 1 to be fastened to a vertical support surface. Inthat case, the stand 3 would not be used. The dispenser of thisembodiment may therefore be positioned on a horizontal surface by usingthe stand 3, or mounted on a vertical surface, without the stand 3. Inuse, the napkin stack is loaded into the dispenser with the cover 2 inopen position, after which the cover 2 is closed. When the one-by-oneface plate 4 is used, a first napkin is withdrawn in whole or in partthrough the dispensing opening 5, with the aid of the side extension 6thereof. The interfolding causes two adjacent panels of the next napkinto project through the dispensing opening, such that a user will be ableto take only one napkin at a time. This dispensing mode discouragesusers from withdrawing more napkins than are needed, and correspondinglyreduces waste. When the dispenser is almost empty, the transparent cover2 will reveal that condition to employees of the establishment, so thatthe dispenser can be refilled.

While the present invention has been described in connection withvarious preferred embodiments thereof, it is to be understood that thoseembodiments are provided merely to illustrate the invention, and shouldnot be used as a pretext to limit the scope of protection conferred bythe true scope and spirit of the appended claims.

1. A stack of interfolded absorbent sheet products, comprising aplurality of absorbent sheets each of which is itself folded at leasttwice about axes that are perpendicular to one another, the absorbentsheets moreover comprising an embossed surface relief of a predeterminedpattern or design, wherein each of said absorbent sheets within saidstack comprises at least one pair of panels sandwiched between a pair ofadjacent panels of another of said absorbent sheets within said stack,wherein each of said absorbent sheets is a paper napkin having only twofolds, the two folds each bisecting the napkin into two equal parts andbeing perpendicular to one another, thereby to form a napkin having fourequal panels, and wherein each of said absorbent sheets is entirelydetached from all other absorbent sheets within said stack.
 2. The stackof interfolded absorbent sheet products according to claim 1, whereineach of said absorbent sheets is a single ply paper napkin having abasis weight of from about 10 to 20 lb.
 3. The stack of interfoldedabsorbent sheet products according to claim 2, wherein said basis weightis from about 11 to about 17 lb.
 4. The stack of interfolded absorbentsheet products according to claim 3, wherein said basis weight is fromabout 12 to about 15 lb.
 5. The stack of interfolded absorbent sheetproducts according to claim 4, wherein said basis weight is about 13 lb.6. The stack of interfolded absorbent sheet products according to claim1, wherein each napkin within said stack receives between two inwardlyfacing adjacent panels a pair of adjacent panels from each of twonapkins disposed respectively above and below said napkin in said stack.7. The stack of interfolded absorbent sheet products according to claim1, wherein said embossed surface relief is applied by embossing rollersduring a converting phase of manufacturing said absorbent sheetproducts.
 8. The stack of interfolded absorbent sheet products accordingto claim 1, wherein said embossed surface relief is applied by TADformation of said absorbent sheets.
 9. The stack of interfoldedabsorbent sheet products according to claim 1, wherein said embossedsurface relief is of a continuous pattern over an entire surface of saidabsorbent sheets.
 10. The stack of interfolded absorbent sheet productsaccording to claim 1, wherein said embossed surface relief is appliedalong a peripheral region of said absorbent sheets.
 11. In combination,a stack of interfolded absorbent sheet products according to claim 1 anda dispenser containing said stack, said dispenser comprising adownwardly-directed opening through which said absorbent sheets may bewithdrawn one at a time.
 12. The combination according to claim 11,wherein solely the weight of said stack urges said sheets toward saiddownwardly-directed dispensing opening.
 13. The combination according toclaim 11, wherein said dispenser comprises a main body portion housingsaid stack, said main body portion comprising at least one sectionoriented at an oblique angle in relation to a horizontal support surfacefor said dispenser.
 14. A stack of interfolded absorbent sheet products,comprising a plurality of absorbent single ply sheets having a basisweight of from about 10 to 20 lb, each of said absorbent sheets isfolded about axes that are perpendicular to one another, the absorbentsheets moreover comprising an embossed surface relief of a predeterminedpattern or design applied by TAD formation of said absorbent sheets,wherein each of said absorbent sheets within said stack comprises atleast one pair of panels sandwiched between a pair of adjacent panels ofanother of said absorbent sheets within said stack, wherein each of saidabsorbent sheets is a paper napkin having only two folds, the two foldseach bisecting the napkin into two equal parts and being perpendicularto one another, thereby to form a napkin having four equal panels, andwherein each of said absorbent sheets is entirely detached from allother absorbent sheets within said stack.